Copper base alloy



Patented Jan. 2, 1940 PATENT OFFICE COPPER BASE ALLOY Elmore S. Strang and Edward H. Koenig, New Haven, Conn., assignors to The New Haven Copper Company, Seymour, Conn., a corporation of Connecticut Application December 13, 1938, Serial No. 245,410

3 Claims.

The invention relates to alloys and, more particularly, to silicon-copper alloys having improved physical and chemical characteristics.

The invention contemplates, in general, an al- 6 loy having relatively small amounts of nickel and:

silicon, with the remainder substantially all copper. As a specific example, the alloy may containnickel 1.0%, silicon 3.5% and copper 95.5%.

An alloy according to the invention is charac- 1 terized by increased corrosion resistance, hardness, strength, toughness, ductility, low electrical conductivity and excellent welding qualities. The alloy may be either hot worked or cold worked, requiring no special heat treatment in the manufacture or fabrication thereof. This al- 10y has, when soft, excellent drawing and spinning characteristics. 1

The invention further consists in the new and useful combinations of elements and the new and original arrangements and combinations of steps in the process hereinafter described and more particularly set forth in the claims.

As an illustrative embodiment of the invention. an alloy having the above composition may be prepared as follows: The copper and silicon are first charged into a crucible or, furnace and melted and suitably mixed. After the above materials have been melded and mixed, the nickel is added, preferably in such amounts as will go into solution quickly and with no increase in the temperature of the bath.

It is desirable that the mix be melted at a temperature of above 1150 0. Before pouring, the melt preferably is allowed to cool to a temperature between 1120* 0. minimum and 1140 0.

maximum in order in order to obtain sound casting without pipe and which does not spew when freezing. When pouring, it is desirable to use a pouring cup for filling the mould in order to distribute the metal evenly as it flows into the mould and to assist in shrinking the bar, that is, teeming or filling the mould from time to time with additional metal when shrinking occurs, in order to prevent piping. Where it is desirable that the finished alloy be readily machinable, lead is added in small amounts sufiicient to give a lead content in the finished alloy ofapproximately .10 to .50%. However, it is desirable only to add lead where machinability is an important requirement.

of the finished alloy may run from about 1.0 to 5.0%. The remainder will be copper, except when small amounts of lead are added, as above indicated. Although the several constituents all contribute to give the alloys excellent properties, 5 it is believed that the presence of the nickel makes the alloy workable, tough and ductile and improves its elasticity. The silicon makes the alloy more corrosion resistant, improving its hardness, reducing its electrical conductivity and increasing its tensile strength.

Although an alloy having a composition falling anywhere within the above ranges has the excellent characteristics herein pointed out, the alloy containing approximately 1.0% nickel, 3.5% 15 silicon and 95.5% copper is given as a particular embodiment for purposes of illustration.

An alloy of the above composition, when soft drawn or soft rolled, has been found to have a tensile strength of approximately 65,000 PSI, a 50 yield point of 18,000 PSI, an elongation of 60% in two inches, and a hardness on the Rockwell 3" scale with a ball of 40. When hard rol1ed.'- the alloy has been found to have a tensile strength of 118,000 'PSI, a yield point of 78,000 PSI, an elongation of 2% in two inches, and a hardness on the Rockwell B scale with a 1*,"

ball of 100. The modulus of elasticity is 17.4 10 The electrical conductivity is approximately 7%.

.No particular heat treatment is necessary in the fabrication of the material other than the ordinary process anneals. The alloy can be hot rolled or forged at a temperature of at least F. higher than that of many other copper-silicon 35 alloys. For example, this alloy can be rolled at a temperature of around 1600 F. which permits greater reductions between heats than heretofore possible.

At the critical temperature of annealing, 40

namely, 1500 F., without quenching, the material is sumciently softened to permit stretching or patent leveling and flattening when cold. This alloy will permit a greater amount of cold work than many of the usualcopper-silicon alloys. 45 The alloy is inherently resistant to corrosion and by reason of the great hardness obtained without special heat treatment, the alloy has a very high resistance to abrasion. When soft, the alloy has excellent properties for deep drawing and spin- 60 ning operations. I

Some of the commercial uses for this alloy are: tanks or boilers for water or chemicals; paper print rollers on which designs are etched; paper mill quipment, such as paper pulp chests, screen. 66

plates, Jordan or beater bars; leaf springs for electrical contacts and for mechanical uses; thrust bearings for taking shocks; sanitation equipment; textile equipment; turbine blading; pump liners and rods, etc. The alloy can be readily welded electrically and the weld or seam has exceptionally high strength and resistance to corrosion.

While certain novel features of the invention have been disclosed and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. An alloy composed of approximately 3.5% silicon, approximately 1.0% nickel and approximately 95.5% copper, said alloy having a tensile strength range from about 65,000 to 118,000 PSI,

a yield point range from about 18,000 to 78,000 PSI, a modulus of elasticity of 17.4 10 and an elongation range of from about 2 to 60% in two inches.

2. A copper base alloy composed of from about 1.0 to 5.0% silicon, from about 0.5 to 5.0% nickel, with the remainder all copper, said alloy being characterized by high ducitlity, elasticity, tensile strength and hardness, by high'resistance to corrosion and abrasion, and by excellent welding properties.

3. A copper base alloy composed of 1.0 to 5.0% silicon and about 1.0% nickel with the remainder all copper, said alloy being characterized by high ductility, elasticity, tensile strength and hardness, by high resistance to corrosion and abrasion, and by excellent welding properties.

. ELMORE S. STRANG.

EDWARD H. KOENIG. 

